The most prominent nail fungus symptom is a visible change in the appearance of a toe nail or fingernail. Signs of infection (onychomycosis) often begin at the end nearest the tip of the nail, underneath the nail where it naturally separates from the nail bed. This is frequently where fungi gain access to the nail and begin to slowly spread through the layers of nail under the surface. Fungal growth may first appear as a white patch or yellowish discoloration. The color change then typically spreads slowly across the nail and back towards the cuticle.
When the cause of toe nail fungus is a yeast species, rather than a typical fungus, the symptoms can be quite different. Yeast infections often begin at a break in the skin at the edge of the nail, or in a soft moist nail, and involve the soft tissue of the finger as well as the nail at an early stage. A yeast infection of the nail can be very painful with a red swollen finger tip or toe, and possibly the production of pus. A red swollen painful nail or fingertip should be seen by a doctor as soon as possible.
A filamentous fungus is the most common cause of toe nail fungus. A number of different fungi cause this slower, more chronic type of onychomycosis. Though these infections are generally not painful in the early stages, fingers and toes can become quite tender when the infection is advanced. At an advanced stage a typical nail fungus symptom is a thickened, discolored, crumbling nail that may be white, yellow, brown or even black. Infection tends to spread to other nails, and some fungi are also capable of spreading to infect the surrounding skin.
Though many people believe they are familiar enough with a typical nail fungus symptom to diagnose it themselves, other things can cause a very similar picture. Bacterial growth underneath a nail can look green or black, and some nail deformities caused by noninfectious processes can also look a lot like onychomycosis. Even when the problem is nail fungus, it’s a good idea to get a doctor to look at it so that lab testing can determine the exact cause of toe nail fungus – the species of fungus involved. If you believe you have onychomycosis, see your doctor immediately so that you can start treating it properly, early.